The UN civil aviation body said on Friday it was not responsible for issuing warnings about potential dangers such as military conflicts, saying that duty fell to individual nations.

The role of the International Civil Aviation Authority has come under scrutiny after a Malaysian airliner was shot down by a missile on Thursday over eastern Ukraine, killing 298 people.

Montreal-based ICAO rejected suggestions it should have issued a warning about the potential dangers of flying over the area.

"ICAO does not declare airspace safe or unsafe or undertake any other direct operational responsibilities with respect to civilian air services," said spokesman Anthony Philbin.

"It is always the responsibility of our sovereign member states to advise other states of potential safety hazards."

Asked whether ICAO would ever issue warnings about the dangers of missiles, he replied: "It's not our job."

Malaysia's transport minister said earlier that ICAO had shut down a route over eastern Ukraine after the disaster. ICAO said it did not have the power to open or shut routes.

ICAO did issue a warning to airlines in April about flying over Crimea in the wake of the Russian invasion but it cited potential problems with conflicting air traffic controllers, not the risk of violence.

The warning was not an order but rather said "consideration should be given to measures to avoid the airspace".

Malaysia said ICAO had approved the route the doomed airliner took but this appears to be a misreading of what the body does. ICAO issues advisories based on decisions taken by delegates rather than telling members what to do.

"It is up to countries to implement them or not, most countries do ... but ICAO standards are more or less equivalent to a treaty, you can either comply or not as you see fit," said a Canadian expert on aviation law, who asked not to be identified because he was not authorized to speak to the media.

Despite having an expertise in aviation, ICAO is challenged by its inherent structure as a UN body with 190 members, said John Saba, a lecturer at McGill University's Integrated Aviation Management Programme in Montreal.

"The political constraints are beyond them," Saba said. "You have people from different countries who are trying to represent the interest of their country but also hammer out deals.

"To condemn them (ICAO) would be very, very unfair."

Philbin said ICAO would not pass on any information it might receive about airlines avoiding certain parts of the world because "ICAO doesn't really have an operational mandate".

Ukraine had allowed airliners to fly at 32,000 feet (9,753 meters) and higher above the area where the Malaysian flight crashed. US and other officials say the jet was shot down by a surface-to-air missile fired from territory controlled by Russian-backed separatist rebels. - Reuters